Thursday, October 25, 2007

London, Oct. 25: Every successive American government, from President Jimmy Carter to incumbent President George W. Bush, has turned a blind eye to Pakistan’s nuclear programme and allowed Islamabad to build nuclear facilities at Kahuta, near Islamabad, and assemble a vast arsenal of nuclear weapons by diverting US aid money, according to details revealed by investigative journalists Adrian Levy and Catherine Scott-Clark in their new book Deception: Pakistan, the United States and the Global Weapons Conspiracy.

Successive US governments even sanitised reports on Pakistan’s nuclear ambitions and capabilities by their own intelligence agencies by either rewriting them or destroying all evidence painstakingly collected to enable Islamabad achieve its nuclear goals clandestinely, the book claims.

Evidence was destroyed, criminal files were diverted, the US Congress was repeatedly lied to, and in several cases, in 1986 and 1987, presidential appointees even tipped off the Pakistan government to prevent its agents from getting caught in the US Customs Service stings that aimed to catch them buying nuclear components in America, the authors claim.

The so-called rouge nations, Iran, North Korea and Libya, described by US President George W. Bush as the “Axis of Evil,” got their nuclear technology from Pakistan, the authors added. Describing Pakistan as a rouge nation at the epicentre of world destabilisation, the book claims that Pakistan was still busy selling its nuclear secrets in the world market.

In a chilling warning to the world, the authors say: “It will only be a matter of time before the rising tide of Sunni extremism and the fast-flowing current of nuclear exports find common cause and realise their apocalyptic intent. There are plenty of ideologues, thinkers and Islamic strategists who are working towards precisely that goal, and here is a regime in Islamabad that has no hard and fast rules, no unambiguous goals or laws, and no line that cannot be bent and reshaped.”

Describing the genesis of nuclear Pakistan, the authors have written: “It all started with an ambitious young man who could not get a job.” Abdul Qadeer Khan, a metallurgical engineer and the future Father of the Pakistan Bomb, wrote to Zulfikar Ali Bhutto in 1974 offering highly classified blueprints for a radical new nuclear process being developed by a consortium of British, Dutch and German scientists called URENCO.

Smarting over the American refusal to act as Pakistan’s security guarantor against a nuclear attack by India, which had tested its bomb in Pokhran on May 18, 1974, Bhutto grabbed the offer and in October 1975 A.Q. Khan “brought to Pakistan designs, instruction manual and lists of suppliers for both the CNOR and G-2 prototypes” of centrifuges developed by URENCO scientists. Khan, who had given himself a seven-year deadline to build the bomb, chose Kahuta, outside Islamabad, as the site of the enrichment facility, the Engineering Research Laboratories, codenamed Project 706.

The construction of the nuclear facility started in the autumn of 1976. The CIA, the book says, reported about the intense activity in Kahuta to its regional headquarters in Tehran. “Something strange is happening at Kahuta. Construction work is going on at a pace quite uncharacteristic of Pakistan. One can see day-to-day progress.” Western nations kept disregarding warnings about Khan and Pakistan’s network of agents who had begun shopping in Europe and North America for equipment needed for the nuclear facility at Kahuta.

The first warning came from a colleague of his at URENCO’s Almelo centrifuge project, Frits Veerman, in 1975, and then Nico Zondag, who tipped off the Dutch intelligence service. However, there was no response to both the complaints. However, most of the components that Khan and Pakistani agents were buying were not on any IAEA list of nuclear-sensitive equipment due to the fact that the centrifuge technology itself was new at the time. “Greed, lax customs inspections, an overly bureaucratic IAEA, governments’ pursuit of their national interests, and antiquated legislation were all being exploited ruthlessly, and clearly Western governments and suppliers underestimated Pakistan,” say the authors.

The US in 1976 had offered Bhutto a deal to stop his reprocessing project (Pakistan was in talks with France over a reprocessing plant) and offered to share products from a US-supplied facility in Iran. Even at that point, a report ordered by the US State department had concluded that “Pakistan’s nuclear industry is not worrisome now.”

It was only after March 1979, when a German TV channel unmasked A.Q. Khan as the head of Pakistan’s nuclear programme, that then US President Jimmy Carter ordered the CIA to investigate. With the imposition of a Communist government in Afghanistan in 1978 and the Soviet invasion of that country the following year, and the overthrow of the pro-US Shah of Iran by Ayatollah Khomeini in February 1979, Mr Carter’s national security adviser Zbigniew Brzezinski lobbied for a change in US non-proliferation policy in order to fight the Soviets through a proxy war by Afghan rebels. The US by now had a detailed picture of Pakistan’s nuclear programme, but had decided to go on the backfoot to protect its strategic interests in the region. However, the real deceit on the Pakistan nuclear issue began with the Reagan administration.

“US officials converged on Islamabad carrying cash (for the proxy war in Afghanistan routed through the ISI) and with the message that America would ignore Pakistan’s growing nuclear programme,” say the authors. President Reagan insisted that non-proliferation remained a key policy, they add. Reagan officials went on the offensive to prevent any opposition in Congress to its plans to use Pakistan as “a staging post to bleed the Soviets.”

In order to get Congress to agree to unprecedented aid for Pakistan, Reagan advisers began promoting the theory that the “way to gain assurance that A.Q. Khan would roll back the nuclear programme was to give Islamabad F-16 jets and money.” The theory rapidly bloomed into a complex conspiracy as the US State department officials started “actively obstructing other arms of government which could not help but fall over intelligence about Pakistan’s nuclear trade.”

New Delhi: India on Thursday began weaponisation of fighter aircraft with the indigenous Light Combat Aircraft 'Tejas' successfully test-firing a close combat air-to-air missile off the Goa coast for the first time.

The LCA fired a Russian R-73 air-to-air missile during a technology demonstrator flight. It was the most significant milestone for the 'Tejas' programme.

The historic flight was done on Tejas prototype vehicle PV-1, piloted by the Chief Test Pilot of the National Flight Test Centre ADA, Gp Capt N Harish. The test-firing was done at 7 km altitude and 0.6 Mach.

The flight test was conducted from the mobile telemetry vehicle where all the aircraft, systems and weapon data were closely monitored.

Quick analysis of the data revealed that it was a ‘text book’ launch where the systems performance matched the predictions well.

The historic event marks the beginning of weaponisation, which is the focus of the current initial operational clearance (IOC) phase of the programme, he said.

A Defence Ministry official said the much-delayed indigenous fighter is now almost ready for flight certification. The initial operational configuration for the fighter is expected between 2011-12 and the aircraft will be fully operational by 2013.

Air-to-air missile integration and testing, especially on a fly-by-wire aircraft, is a very complex task involving interfaces with aerodynamics, engine air intake, control laws, flight control system, avionics system, electrical and other general system of aircraft.

The Indian Air Force has already placed orders for 20 LCAs with the Hindustan Aeronautics Limited with a provision for buying another 20 in the same contract.

Tejas successfully test-fires R-73 air-to-air miss

Thursday, 25 October , 2007, 22:39

New Delhi: In a major breakthrough, India's indigenous Light Combat Aircraft (LCA), Tejas, on Thursday successfully test-fired for the first time a close combat air-to-air missile off the Goa coast.

The LCA fired a Russian R-73 air-to-air missile during a technology demonstrator flight off the Goa coast.

Hailing it as a "milestone", a Defence Ministry spokesman said this heralds the start of the weaponisation of Tejas.

The much-delayed indigenous fighter is now almost ready for flight certification, officials said.

The initial operational configuration for the fighter is expected between 2011-12 and the aircraft will be fully operational by 2013.

The Indian Air Force has already placed orders for 20 LCAs with the Hindustan Aeronautics Limited with a provision for buying another 20 in the same contract.

Sunday, October 21, 2007

Jet fighters began to be equipped with airborne radars in the early 1960's. Radars provided better detection capability than human eyes and facilitated guidance of air to air missiles which could be used to attack enemy fighters at ranges considerably larger than the few hundred yards that aircraft cannons were effective up to.

Dish Antenna Radars

Early jet fighter, like the MiG-21, employed mechanically steered concave reflector antennas colloquially referred to as dish antennas. A concave reflector antenna is a simple and effective solution for generating a shaped radar beam as well as efficiently gathering any reflected energy from it.

Dish antennas, however, have their limitations. Their to and fro steering mechanisms are expensive to fabricate to the high accuracies required. Such steering mechanisms are also prone to frequent failures. In other words they have a relatively short Mean Times Between Failure (MTBF) of around 60 to 300 hours.

Another problem with dish antennas radars is that they have fairly large side-lobes which leads to signal losses and reduces their sensitivity.

Finally, dish antennas do a good job not just of shaping their transmitter beams and gathering reflected energy from it but they are equally efficient at reflecting radar energy from enemy radars! In other words they are as good with detecting the enemy as they are with letting the enemy detect them.

The Evolving Threat

Initially jet fighters were equipped with airborne radars purely for air to air combat. As long as the threat that a fighter aircraft was attempting to counter were enemy fighter aircrafts, first generation radars with dish antennas were effective. However, the introduction of long cruise missiles by the former Soviet Union in the 1970s changed the equation dramatically. The smaller size of the cruise missile, and the consequent reduced radar signature gave cruise missiles a good chance of penetrating the fighter air cover over US carrier groups and hitting home with devastating effects.

In order to effectively engage cruise missile the detection and guidance capability of an airborne radar needed to be stepped up dramatically.

As the threat evolved so did airborne radars. In order to reduce the sidelobes associated with dish antennas as well as reduce their reflectivity planar or slotted array antennas began to be developed in the 1970s.

Planar Array Antennas

Planar array antennas, like dish antennas, are also mechanically steered but they use a flat rather than concave receiver to gather the reflected radar energy. A flat panel reflector scatters the radar energy impinging on it from hostile radars, rather than sending it back as a well focused beam.

Planar arrays use an array of very simple slot antennas. They achieve their focusing effect by introducing and manipulating a time delay into transmissions from each antenna. A complex network of microwave waveguides on the rear surface of the array is used to achieve this. The controlled time delays result in a desired fixed beam shape with much smaller sidelobes compared to a concave reflecting antenna. The key to slotted array antennas is the time delay caused by waveguides. The signal that they transmit is in phase.

Since a planar array antenna is a flat plate, it tends to act like a flat panel reflector to impinging transmissions from hostile radars and thus produce a lower radar signature than a concave antenna.

However, mechanical steering of planar array antennas continued to be a problem.

The Zhuk-ME radar developed by Phazotron-NIIR design burea and fitted on the MiG 29 is an example of slotted array antenna radar. Similarly the AN/APG-65/73 radar fitted on the F/A-18A and the APG-66 radar fitted on the F-16A are slotted array radars.

The AN/APG-65 radar is an all-weather multimode slotted array radar fitted on F/A-18A. It is used for both air-to-air and air-to-surface missions.

Phased Array Radars

The key to improving radar capability lay in electronic steering of the radar beam a technique that first began to be employed in ground based anti missile radars in the 1970s. Such radars employ a group of antennas in which the relative phases of the respective signals feeding the antennas are varied in such a way that the effective radiation pattern of the array is reinforced in a desired direction and suppressed in undesired directions. Such radars are referred to as phased array radars, since they employ an array of antennas that work using a shift in the signal phase.

By the early 1980s the technology had been mastered to an extent where it could be employed in airborne radars.

Electronic steering and shaping of a beam provides unprecedented beam agility - beam shape and direction can be digitally controlled by a computer within a matter of tens of milliseconds. Such beam agility makes it possible for one phased array radar to act as multiple radars each with its own beam shape and scan pattern! This is referred to as interleaving radar modes. The same radar can be tracking for airborne threats using one beam shape and scan pattern while searching for ground targets using another beam shape and scan pattern.

The Russian NIIP N-011M Bars radar fitted on the Su-30MKI and the NIIP Bars-29 radar proposed to be fitted on the MiG-29M2 being offered to the IAF are examples of phased array radars. The B-1B Bone has flown since the 1980s with an AN/APQ-164 radar, fitted with an electronically steered array. The B-1A Batwing also exploits this technology in its AN/APQ-181 multimode attack radar.

NIIP N-011M Bars radar fitted on the Su-30MKI is capable of detecting and tracking up to 15 air targets, while simultaneously attacking four of them

Phased array radars also referred to as passive array radars, represent a big leap forwards. Using beam steering they provide stealth, interleaving modes and reliability. However, the shift in phase of the radar signal comes at a cost. High-power phase control leads to losses in the signal and a consequent reduction in radar sensitivity. Typical total losses in early systems resulted in a factor of 10 reductions in radiated power; in modern systems these losses are still in the factor of 5 ranges.

AESA

An Active Electronically Steered Array (AESA) takes the concept of using an array antenna a step further. Instead of shifting the phase of signals from a single high power transmitter AESA employs a grid of hundreds of small "transmitter-receiver (TR)" modules that are linked together by high-speed processors.

Each TR module has its own transmitter, receiver, processing power, and a small spikelike radiator antenna on top. The TR module can be programmed to act as a transmitter, receiver, or radar. The TR modules in the AESA system can all work together to create a powerful radar, but they can do different tasks in parallel, with some operating together as a radar warning receiver, others operating together as a jammer, and the rest operating as a radar. TR modules can be reassigned to any role, with output power or receiver sensitivity of any one of the "subsystems" defined by such temporary associations proportional to the number of modules.

AESA provides 10-30 times more net radar capability plus significant advantages in the areas of range resolution, countermeasure resistance and flexibility. In addition, it supports high reliability / low maintenance goals, which translate into lower lifecycle costs. Since the power supplies, final power amplification and input receive amplification, are distributed, MTBF is significantly higher, 10-100 times, than that of a passive ESA or mechanical array. This results in higher system readiness and significant savings in terms of life cycle cost of a weapon system, especially a fighter.

The use of multiple TR modules also means failure of up to 10% of the TR modules in an AESA will not cause the loss of the antenna function, but merely degrade its performance. From a reliability and support perspective, this graceful degradation effect is invaluable. A radar which has lost several TR modules can continue to be operated until scheduled downtime is organized to swap the antenna.

Technological Leap

AESA technology has not been easy to acquire. It has come from years of research and heavy investments. Improvement of gallium arsenide material and the development of monolithic microwave integrated circuit (MMIC) have been key enablers to the development of AESA technology.

Two prominent early programs in X-band AESA technology development have been the Army family-of-radars program (which provided the basis for the X-band AESAs in the THAAD and GBR radars for theater and national missile defense systems, respectively), and the Air Force programs to produce X-band AESAs for the F-15 and the F-22. The investments in JSF radar technology have also fostered pivotal advances in reducing cost, weight, and mechanical complexity. JSF transmit/receive (T/R) modules are referred to as "fourth generation" T/R module technology.

As can be expected, the technology comes at a cost. Each TR module is an independent radar. Initial cost of a TR module was reportedly around $2000. Fighter radars are usually in the 1000 to 2000 modules size range. In other words just the radar antenna could cost as much as $4 million.

Indian defence scientists have taken up a new cruise missile development programme. The missile named Nirbhay (The Fearless) is in the same class as the US's Tomahawk and will have a range that is 300km longer than Pakistan's Babur.

Nirbhay is India's seventh missile development project after the Agni series, the Prithvi series, Brahmos (in a joint venture with Russia), Akash, Trishul and Nag. The last three were part of the Integrated Guided Missile Development Programme founded by A.P.J. Abdul Kalam. Nirbhay is being developed alongside Astra, an air-to-air missile designed to hit targets beyond visual range.

A cruise missile can be guided to a target. A ballistic missile is fired at a pre-determined target. Nirbhay will carry onboard a terrain-identification system that will map its course and relay the information to its guidance and propulsion systems. â€œEvery modern military needs to have missile options. The requirement for Nirbhay was projected by all three armed forces to fill a gap in our missile programme,â€ Avinash Chander, the director of the Advanced Systems Laboratory, Hyderabad, who is in charge of the project, told The Telegraph in Delhi today.

Nirbhay will be a terrain-hugging missile capable of avoiding detection by ground-based radar. It would have a range of 1,000km. We have Brahmos, which is a supersonic cruise missile and the need was felt for a subsonic cruise missile that will be capable of being launched from multiple platforms in land, air and sea, Chander said.

In the schedule drawn up for Nirbhay, a technology demonstrator is slotted for early 2009. Chander said the design for the system is complete and hardware preparations are onâ€. He said Nirbhay would weigh around 1,000kg and travel at 0.7 mach (nearly 840kmph) and would be capable of delivering 24 different types of warheads. The Pakistani subsonic cruise missile Babur (also called Hatf VII) has ranges of 500 to 700km. The US's Tomahawk has many versions, the latest of which has ranges in excess of 1,500km.